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  1. #1

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    Can RA4 paper be fogged by drying spray paint?

    I have just made a dispenser for photo paper rolls. I spray painted it inside with a can of flat black paint. As a last step before loading a $1000 roll of FujiFlex, I had a silly idea to test the dispenser for light leaks. So I folded a sheet of 20x24 CA paper into a cylinder and put it into the dispenser. I left it there for two days. This evening I processed the sheet of paper and was horrified to discover that the lower left corner of the paper is nearly black with dark red tinge. I suspect this corner was sitting on the bottom of the box towards the back. Anyway, I find it rather incredible that the corner is nearly absolutely black while the rest of the sheet is perfectly while. Somehow I don't think that there should be such strong light leaks at the bottom towards the back of the dispenser. My suspicion is that it's the vapors from not completely dried paint fogged the paper that was touching the bottom. Is that possible, or is it more likely that it's still a light leak?

    P.S. Sorry for crappy iPad photos.
    Attached Thumbnails Attached Thumbnails photo1.JPG   photo2.JPG  

  2. #2
    polyglot's Avatar
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    If it were vapours, the fogging should be more diffuse. Have you tried airing it out for a couple days then re-testing?

  3. #3

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    I would bake that box for a while, if you spray painted wood, it's going to outgas for weeks as the solvents in the paint soaked into the wood. I'd say leave it out in the sun for a week, but it's the wrong time of the year in Oregon. I guess a small fan heater will help.

    Black with redish tint and edges sure sounds like a light leak, it really doesn't take much light either if it sat for a week in a room. 2 min in a beseler drum with the light reflecting thru the fill spout from the a 2x40 watt fixture on the ceiling leaves a nice red spot.

    BTW black foam neoprene weather stripping helps keep the light out, it works very well on the black plastic commercial paper safes.
    Bob

  4. #4
    AgX
    AgX is online now

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    One could also use a hot air gun.

  5. #5

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    Do the test again, but with the box in total darkness. Write on the paper which way you put it in. If the problem goes away, the box probably has a light leak.

  6. #6

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    Oh, never mind. I just figured it out with a little bit of detective work. There are crease marks on the paper right on the boundary of the fogged part. It looks like the corner of the paper was pinched by the door as it was closing. This means that the light trap IS working, and everything is fine! I'm ready to use the dispenser!!!!
    That's the problem with loading and unloading the paper in complete darkness - you have no idea what is going on.

  7. #7

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    I'd still let it outgas for a number of weeks. Those MEK fumes take a long time to dissipate. And even
    if the paper doesn't get fogged, it might be seriously compromised in terms of dye permanence.

  8. #8

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    Good idea Drew! I was planning to put another coat of paint on it this week. And I will be traveling for next couple of weeks, so it will come out just perfect!

  9. #9

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    Better safe than sorry. I was hoping to work on my own trimmer a bit more during this particular holiday so I can soon start calibrating my own 40-inch roll of Supergloss. I want to see how the
    material works with my interneg experiments with chromes, as well as from conventional masked negs.

  10. #10

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    Quote Originally Posted by DREW WILEY View Post
    Better safe than sorry.
    You can say that again. I tried to cut a piece from the roll in our bathroom so that I can test it. Boy was I in for a surprise! The roll is surprisingly heavy and unwieldy. And I simply could not cut it with my handheld olfa rotary trimmer, so I had to use the scissors and do an ugly cut through. I was all covered in sweat by the time I was done - it felt like wrestling a bear in the dark.
    That's the reason I started building this dispenser. The days of cut sheet paper are quickly passing, so we need to adapt.

    I'm thinking about using this power trimmer to cut the paper when I pull it from the dispenser:

    http://www.sears.com/skil-3.6v-li-io...3&blockType=G3

    The idea is to measure the needed length and then trim it by the edge of the dispenser. Don't know yet how well it will work, but that's the idea. Can you share what you are using?

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